Flame retardant polycarbonate composition

ABSTRACT

An improved flame retardant polycarbonate composition of an aromatic carbonate polymer in admixture with an organic alkali metal salt or an organic alkaline earth metal salt or mixture thereof, which composition has in admixture therewith fibrous glass.

This is a continuation, of application Ser. No. 496,127, filed Aug. 9,1974, now abandoned.

This invention is directed to an improved flame retardant polycarbonatecomposition of an aromatic carbonate polymer in admixture with anorganic alkali metal salt or an organic alkaline earth metal salt ormixture thereof, the improvement which comprises having in admixturewith the polycarbonate fibrous glass in sufficient quantity to renderthe polycarbonate composition non-dripping.

BACKGROUND OF THE INVENTION

In the art, there are many flame retardant additives which are employedby mixing with polycarbonate to render such materials self-extinguishingor flame retardant. Such flame retardant additives are employed invarying amounts in order to be effective in extinguishing burning ofthose products which are combustible.

However, even if the polycarbonate does not burn, in flame, it may driphot particles which can ignite material below it.

DESCRIPTION OF THE INVENTION

It has been suprisingly discovered that an aromatic polycarbonate madeflame retardant by incorporating with the aromatic polycarbonate organicalkali metal salts or organic alkaline earth metal salts or mixturesthereof can be rendered nondripping by admixing the flame retardantpolycarbonate with fibrous glass.

By glass fibers, it is understood that glass silk, as well as all glassfiber materials derived therefrom including glass fiber fabrics,rovings, stable fibers and glass fiber mats are included. The length ofthe glass filaments and whether or not they are bundled into fibers andthe fibers bundled in turn to yarns, ropes or rovings, or woven intomats, and the like, are also not critical to the invention. However,when using fibrous glass filaments, they may first be formed andgathered into a bundle known as a strand. In order to bind the filamentsinto a strand so that the strand can be handled, a binder or bindingagent is applied to the glass filaments. Subsequently, the strand can bechopped into various lengths as desired. It is convenient to use thestrands in lengths of from about 1/8" to about 1" long, preferably lessthan 1/4" in length. These are called chopped strands. Some of thesebinding agents are polymers such as polyvinyl acetate, particularpolyester resins, polycarbonates, starch, acrylic melamine, polyvinylchloride, polyethylene oxide or polyvinyl alcohol. Preferably, thecomposition contains from about 1 to about 50 weight percent of theglass fibers.

The composition of the instant invention may also include thefluorinated polyolefin as described in copending application of CharlesA. Bialous, John B. Luce and Victor Mark, Ser. No. 496,128 filedconcurrently herewith and now abandoned for continuation applicationSer. No. 949,964 filed Oct. 10, 1978, both of said applications assignedto the same assignee as the present invention. Also, the composition ofthe instant invention may include the siloxanes described in copendingapplication of Charles A. Bialous, John B. Luce and Victor Mark, Ser.No. 496,115 filed Aug. 9, 1974 (now U.S. Pat. No. 3,971,756) filedconcurrently herewith and assigned to the same assignee, as the presentinvention. Applications Ser. No. 496,128 and Ser. No. 496,115 areincorporated herein by reference. Further, the instant composition caninclude both fluorinated polyolefin and siloxanes.

The organic alkali metal and alkaline metal salts employed herein arefully described in the following applications:

Application (A) of Victor Mark and Thomas J. Hoogeboom, Ser. No. 429,643filed Dec. 28, 1973 titled A Flame Retardant Polycarbonate Composition,now U.S. Pat. No. 3,933,734.

This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of either monomeric orpolymeric aromatic sulfonic acids, or mixtures thereof.

Application (B) of Victor Mark, Ser. No. 429,121 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,948,851.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of either monomeric orpolymeric aromatic sulfonesulfonic acids, or mixtures thereof.

Application (C) of Victor Mark, Ser. No. 429,642 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,926,908.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of sulfonic acids ofaromatic ketones, or mixtures thereof.

Application (D) of Victor Mark, Ser. No. 429,166 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to theassignee as the present invention and now U.S. Pat. No. 3,919,167. Thisapplication discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of heterocyclic sulfonicacids, or mixtures thereof.

Application (E) of Victor Mark, Ser. No. 429,125 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now abandoned. Thisapplication discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the alkali metal salts of halogenatedmethanesulfonic acids or mixtures thereof, or mixtures of the alkalimetal salts and the alkali earth metal salts.

Application (F) of Victor Mark, Ser. No. 429,644 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 4,066,618.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be metal salts of a halogenatednon-aromatic carboxylic acid or mixtures thereof.

Application (G) of Victor Mark, Ser. No. 429,163 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,909,490.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of sulfonic acids ofaromatic sulfides, or mixtures thereof.

Application (H) of Victor Mark, Ser. No. 429,128 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,953,396.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of either monomeric orpolymeric aromatic ether sulfonic acids, or mixtures thereof.

Application (I) of Victor Mark, Ser. No. 429,645 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,931,100.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of aliphatic andolefinic sulfonic acids, and mixtures thereof.

Application (J) of Victor Mark, Ser. No. 429,126 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,978,024.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of either monomeric orpolymeric phenol ester sulfonic acids, or mixtures thereof.

Application (K) of Victor Mark, Ser. No. 429,164 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 4,069,201.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of unsubstituted orhalogenated oxocarbon acids, or mixtures of these.

Application (L) of Victor Mark, Ser. No. 429,127 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,953,399.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of sulfonic acids ofmonomeric and polymeric aromatic carboxylic acids and esters, andmixtuures thereof.

Application (M) of Victor Mark, Ser. No. 429,165 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,917,559.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of halocycloaliphaticaromatic sulfonic acids.

Application (N) of Victor Mark, Ser. No. 429,646 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,951,910.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of either monomeric orpolymeric aromatic amide sulfonic acids, or mixtures thereof.

Application (O) of Victor Mark, Ser. No. 429,120 filed Dec. 28, 1973titled A Flame Retardant Polycarbonate Composition and assigned to thesame assignee as the present invention and now U.S. Pat. No. 3,940,366.This application discloses a flame retardant polycarbonate compositioncomprising in admixture an aromatic carbonate polymer and a flameretardant additive which may be the metal salts of either monomeric orpolymeric aromatic sulfonic acids, or mixtures thereof.

Applications A through O are incorporated herein by reference. The metalsalts of any of these applications as well as mixtures of any of themetal salts of any of the applications may be used.

Preferred salts include sodium 2,4,5-trichlorobenzene sulfonate; sodiumbenzene sulfonate; disodium naphthalene-2,6-disulfonate; sodiump-iodobenzenesulfonate; sodium 4,4'-dibromobiphenyl-3-sulfonate; sodium2,3,4,5,6-pentachloro-betastyrenesulfonate; sodium4,4'-dichlorodiphenylsulfide-3-sulfonate; disodiumtetrachlorodiphenyletherdisulfonate; disodium4,4'-dichlorobenzophenone-3,3'-disulfonate; sodium2,5-dichlorothiophene-3-sulfonate; sodium salt ofdiphenylsulfone-3-sulfonic acid; sodium dimethyl2,4,6-trichloro-5-sulfoisophthalate; potassium salt of the sulfonic acidof dichlorophenyl 2,4,5-trichlorobenzene sulfonate; calcium salt of2,4,5-trichlorobenzenesulfonanilide-4'-sulfonate; sodium4'[1,4,5,6,7,7-hexachlorobicyclo-[2.2.1]-hept-5-en-endo-2-yl]benzenesulfonate; disodium hexafluoroglutarate; disodium chloranilate;and mixtures thereof. These salts are used in amount of from 0.01 toabout 10 weight percent based on the weight of the aromatic carbonatepolymer composition.

The aromatic carbonate polymers employed in the practice of thisinvention are homopolymers and copolymers that are prepared by reactingthe dihydric phenol with a carbonate precursor. The dihydric phenolsthat can be employed are bisphenols such as bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl) propane (hereinafter referred to asbisphenol-A), 2,2-bis(4-hydroxy-3-methylphenyl) propane,4,4-bis(4-hydroxyphenyl) heptane, 2-2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl) propane, etc., dihydricphenol ethers such as bis(4-hydroxyphenyl) ether, bis(3,5-dichloro-4-hydroxyphenyl) ether, etc.; dihydroxydiphenyls such asp,p'-dihydroxydiphenyl, 3,3'-dichloro-4,4'-dihydroxydiphenyl, etc.;dihydroxyaryl sulfones such as bis(4-hydroxyphenyl) sulfone,bis(3,5-dimethyl-4-hydroxyphenyl) sulfone, etc., dihydroxy benzene,resorcinol, hydroquinone, halo- and alkyl-substituted dihydroxy benzenessuch as 1,4-dihydroxy-2,5-dichlorobenzene,1,4-dihydroxy-3-methylbenzene, etc., and dihydroxy diphenyl sulfoxidessuch as bis(4-hydroxyphenyl) sulfoxide,bis-(3,5-dibromo-4-hydroxyphenyl) sulfoxide, etc. A variety ofadditional dihydric phenols are also available to provide carbonatepolymers and are disclosed in U.S. Pat. Nos. 2,999,835; 8,028,365 and3,153,008. Also suitable for preparing the aromatic carbonate polymersare copolymers prepared from any of the above copolymerized withhalogen-containing dihydric phenols such as2,2-bis(3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl) propane, etc. It is of course possible toemploy two or more different dihydric phenols or a copolymer of adihydric phenol with glycol or with hydroxy or acid terminatedpolyester, or with a dibasic acid in the event a carbonate copolymer orinterpolymer rather than a homopolymer is desired for use in thepreparation of the aromatic carbonate polymers of this invention. Alsoemployed in the practice of this invention may be blends of any of theabove materials to provide the aromatic carbonate polymer.

The carbonate precursor may be either a carbonyl halide, a carbonateester or a haloformate. The carbonyl halides which can be employedherein are carbonyl bromide, carbonyl chloride and mixtures thereof.Typical of the carbonate esters which may be employed herein arediphenyl carbonate, di-(halo-phenyl) carbonates such asdi-(chlorophenyl) carbonate, di-(bromophenyl) carbonate,di-(trichlorophenyl) carbonate, di-(tribromophenyl) carbonate, etc.,di-(alkylphenyl) carbonate such as di-(tolyl) carbonate, etc.,di-(naphthyl) carbonate, di-(chloronaphthyl) carbonate, phenyl tolylcarbonate, chlorophenyl chloronaphthyl carbonate, etc., or mixturesthereof. The haloformates suitable for use herein includebis-haloformates of dihydric phenols (bischloroformates of hydroquinone,etc.) or glycols (bishaloformates of ethylene glycol, neopentyl glycol,polyethylene glycol, etc.). While other carbonate precursors will occurto those skilled in the art, carbonyl chloride also known as phosgene ispreferred.

Also included are the polymeric materials of a dihydric phenol, adicarboxylic acid and carbonic acid. These are disclosed in U.S. Pat.No. 3,169,121 which is incorporated herein by reference.

The aromatic carbonate polymers of this invention are prepared byemploying a molecular weight regulator, an acid acceptor and a catalyst.The molecular weight regulators which may be employed in carrying outthe process of this invention include phenol, cyclohexanol, methanol,para-tertiarybutylphenol, parabromophenol, etc. Preferably, phenol isemployed as the molecular weight regulator.

A suitable acid acceptor may be either an organic or an inorganic acidacceptor. A suitable organic acid acceptor is a tertiary amine andincludes such materials as pyridine, triethylamine, dimethylaniline,tributylamine, etc. The inorganic acid acceptor may be one which can beeither a hydroxide, a carbonate, a bicarbonate, or a phosphate of analkali or alkali earth metal.

Obviously other materials can also be employed with the aromaticcarbonate polymer of this invention and include such materials asanti-static agents, pigments, mold release agents, thermal stabilizers,ultraviolet light stabilizers, reinforcing fillers and the like.

The composition of this invention is prepared by admixing the aromaticcarbonate polymer with the organic alkali metal or alkaline earth metalsalts and the fibrous glass.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The following examples are set forth to illustrate more clearly theprinciple and practice of this invention to those skilled in the art.Unless otherwise specified, where parts or percents are mentioned, theyare parts or percents by weight.

EXAMPLE I

A polycarbonate composition is prepared by extruding a homopolymer of2,2-bis(4-hydroxyphenyl) propane (hereinafter referred to asbisphenol-A) prepared by reacting essentially equimolar amounts ofbisphenol-A and phosgene in an organic medium with triethylamine; sodiumhydroxide, and phenol, under standard conditions. The resulting polymeris then fed to an extruder, which extruder is operated at about 265° C.,and the extrudate is comminuted into pellets.

The pellets are then injection molded at about 315° C. into test bars ofabout 5 in. by 1/2 in. by about 1/16-1/8 in. thick. The test bars (5 foreach additive listed in the Table) are subject to the test procedure setforth in Underwriter' Laboratories, Inc. Bulletin 94, Burning Test forClassifying Materials (hereinafter referred to as UL-94). In accordancewith this test procedure, materials so investigated are rated eitherUL-94 V-O, UL-94 V-I, UL-94 V-II, based on the results of 5 specimens.The criteria for each UL-94 V rating per UL-94 is briefly as follows:

"UL-94 V-O":

Average flaming and/or glowing after removal of the igniting flame shallnot exceed 5 seconds and none of the specimens shall drip particleswhich ignite absorbent cotton.

"UL-94 V-I":

Average flaming and/or glowing after removal of the igniting flame shallnot exceed 25 seconds and none of the specimens shall drip particleswhich ignite absorbent cotton.

"UL-94 V-II":

Average flaming and/or glowing after removal of the igniting flame shallnot exceed 25 seconds and the specimens drip flaming particles whichignite absorbent cotton.

In addition, a test bar which continues to burn for more than 25 secondsafter removal of the igniting flame is classified, not by UL-94, but bythe standards of the instant invention, as "burning." Further, UL-94requires that all test bars must meet the UL-94 V type rating to achievethe particular rating. Otherwise, the 5 bars receive the rating of theworst single bar. For example, if one bar is classified as UL-94 V-IIand the other four (4) are classified as UL-94 V-O, then the rating forall 5 bars is UL-94 V-II.

The results are shown in the Table.

EXAMPLE II

To the polycarbonate of Example I is added 0.5 parts of sodium2,4,5-trichlorobenzenesulfonate. The mixture is extruded, molded, andtested in the same manner as described in Example I.

EXAMPLE III

To the polycarbonate of Example I is added 0.5 parts of sodium2,4,5-trichlorobenzenesulfonate and 6.0 parts of fibrous glass. Themixture is extruded, molded and tested in the same manner as describedin Example I.

The remaining compositions are prepared by the methods of Examples I toIII.

    __________________________________________________________________________                                              FLAME                                                                         OUT  NO. OF                                                                   TIME DRIP                           EXAM-                                GLASS                                                                              Sec. PER 5                          PLE  SALT ADDITIVE              PARTS                                                                              PARTS                                                                              (Avg)                                                                              BARS RATING                    __________________________________________________________________________    I    --                         --   --   13.4 10   Burning                   II   Sodium 2,4,5-trichlorobenzene sulfonate                                                                  0.5  --   3.4  8    UL-94 VII                 III  Sodium 2,4,5-trichlorobenzene sulfonate                                                                  0.5  6.0  4.8  0    UL-94 V-O                 IV   Sodium benzenesulfonate    1.0  8.0  5.0  0    UL-94 V-O                 V    Disodium napthalene-2,6-disulfonate                                                                      1.0  6.0  4.6  0    UL-94 V-O                 VI   Disodium tetrachlorodiphenyletherdisulfonate                                                             0.5  --   4.4  2    UL-94 V-II                VII  Disodium tetrachlorodiphenyletherdisulfonate                                                             0.5  8.0  4.7  0    UL-94 V-O                 VIII Sodium 2,3,4,5,6-pentachloro-betastyrenesulfonate                                                        0.5  4.0  3.6  0    UL-94 V-O                 IX   Sodium 4,4'-dichlorodiphenylsulfide-3-sulfonate                                                          0.5  10.0 4.6  0    UL-94 V-O                 X    Disodium 4,4'-dichlorobenzophenone-3,3'-disulfonate                                                      0.5  6.0  4.6  0    UL-94 V-O                 XI   Sodium 2,5-dichlorothiophene-3-sulfonate                                                                 0.3  8.0  3.2  0    UL-94 V-O                 XII  Sodium diphenylsulfone-3-sulfonate                                                                       0.4  8.0  3.3  0    UL-94 V-O                 XIII Sodium dimethyl 2,4,6-trichloro-5-sulfoisophthalate                                                      1.0  6.0  4.0  0    UL-94 V-O                 XIV  Potassium salt of the sulfonic acid of dichlorophenyl                                                    0.3  6.0  5.0  0    UL-94 V-O                       2,4,5-trichlorobenzenesulfonate                                         XV   Calcium 2,4,5-trichlorobenzenesulfonanilide-4'-sulfonate                                                 1.0  7.0  4.9  0    UL-94 V-O                 XVI  Sodium 4'[1,4,5,6,7,7-hexachlorobicyclo-[2.2.1]-                                                         1.0  3.0  3.8  0    Ul-94 V-O                       hept-5-en-endo-2-yl]benzenesulfonate                                    XVII Disodium hexafluoroglutarate                                                                             1.0  2.0  5.6  0    UL-94 V-I                 XVIII                                                                              Disodium chloranilate      0.2  6.0  4.3  0    UL-94                     __________________________________________________________________________                                                        V-O                   

As can be seen from the data in the Table, when the polycarbonatecompositions contain the fibrous glass in addition to the flameretardant additives, the polycarbonate does not drip and is rated eitherUL-94 V-O, or UL-94 V-I.

Other flame retardant additives can be substituted for those of theTable with similar results.

It will thus be seen that the objects set forth above among those madeapparent from the preceding description are efficiently attained andsince certain changes may be made in carrying out the above process andin the composition set forth without departing from the scope of thisinvention, it is intended that all matters contained in the abovedescription shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:
 1. An improved halogen-free flame-retardantpolycarbonate composition, said composition comprising an aromaticpolycarbonate in admixture with about 0.01 to about 10.0 weight percentbased on the weight of said polycarbonate of an organic alkali metalsalt or an organic alkaline earth metal salt, said salts being derivedfrom acids selected from the group consisting ofunsubstituted monomericor polymeric aromatic sulfonic acids, monomeric or polymeric aromaticsulfonesulfonic acids, sulfonic acids of aromatic ketones, heterocyclicsulfonic acids, sulfonic acids of aromatic sulfides, monomeric orpolymeric aromatic ether sulfonic acids, olefinic sulfonic acids,monomeric or polymeric phenol ester sulfonic acids, unsubstituted orhalogenated oxocarbon acids, sulfonic acids of monomeric and polymericaromatic carboxylic acids and esters, halocycloaliphatic aromaticsulfonic acids, monomeric or polymeric aromatic amide sulfonic acids,monomeric or polymeric aromatic sulfonic acids,or mixtures thereof, saidimprovement comprising including in admixture in said polycarbonatecomposition a fibrous glass in an amount of about 1.0 to about 50.0weight percent based upon the total weight of said polycarbonatecomposition such that said polycarbonate composition is renderednon-dripping in addition to being flame retardant.
 2. The composition ofclaim 1 wherein said fibrous glass is present in an amount of about 2 toabout 10 weight percent.
 3. The composition of claim 1 wherein theorganic alkali metal salt is sodium 2,4,5-trichlorobenzenesulfonate. 4.The composition of claim 1 wherein the organic alkali metal salt issodium benzenesulfonate.